The present invention relates to fluorine-containing triarylphosphine oxide derivatives and preparing method thereof. Particularly, the present invention relates to both fluorine- and phosphine oxide-containing triarylphosphine oxide derivatives which can be utilized in preparing polyimides having excellent adhesion, fire retardancy and low dielectric constant as well as superior thermal stability and mechanical properties, and preparing method thereof.
Since a fluorine atom has high electron-negativity, small Van der Waals radius, similar to that of hydrogen atom, and high bonding energy with other atoms, fluorine containing molecules have low surface tension and thus low intermolecular force, high volatility, and low friction coefficient. Especially, fluorine compounds are known to improve processability, insulating capability, and weather resistance since they have the fluorine atom at the outer shell of the compounds.
Fluorine-containing dianhydrides and diamines are widely used to prepare polyimides having excellent processability and low dielectric constant. A demand of these polyimides is constantly increased in energy relating fields such as nuclear power or solar cell, optical communications, applications using optical materials and semiconductor fields.
Recently, polyimides and polyamides having phosphine oxides have been reported to show improved adhesive and fire retardancy. Bis(3-aminophenyl)phenylphosphine oxide (hereinafter referred to as xe2x80x9cDAPPOxe2x80x9d) disclosed by J. E. McGrath et al. at Virginia Tech is one of the examples (M. F. Martinez-Nuez et al., Polymer Preprint, 35, p. 709 (1994)).
Another example is bis(3-aminophenyl-3,5-bistrifluoromethylphenylphosphine oxide (hereinafter referred to as xe2x80x9cDA6FPPOxe2x80x9d) having a phosphine oxide and 6 fluorines (K. U. Jeong, J. J. Kim and T. H. Yoon, Korea Polymer Journal, 8, 215-223 (2000) and K. U. Jeong, T. H. Yoon, Korean Patent Application No.1999-50831).
Said DA6FPPO has good processability and low dielectric constant, but relatively low glass transition temperature and poor adhesion due to high concentration of fluorine. As a result, there has been a great demand for new monomers which can be used to prepare polyimides having low dielectric constant without lowering Tg, thermal stability and mechanical properties as well as adhesion.
To be free of aforementioned problems, the inventors have extensively studied and prepared bis(3-aminophenyl)[4-(trifluoromethyl)phenyl]phosphine oxide monomer (hereinafter referred to as xe2x80x9cDA3FPPOxe2x80x9d), containing both fluorines and phosphine oxide, which contains less fluorines than DA6FPPO for higher adhesion and Tg without sacrificing excellent mechanical and thermal properties of the conventional polyimides. Therefore, an objective of the present invention is to provide triarylphosphine oxide derivatives having both fluorine(s) and phosphine oxide(s) in order to show superior adhesion and low dielectric constant without sacrificing excellent properties of polyimides.